Lightning-arrester.



J. C. SBAMAN.

LIGHTNING ARRESTBR.

APPLIGATION FILED oo'1.30, 1907.

-9.5 3,301 Patented Mar. 29, 1910.

LIGHTNING-TARRESTE.

953,301. Specification of nomment.v Patented Mar. 29, 1910.

Application tiled October 3G, 1907. Serial No. 399,960.

To all whom it may concern:

Be it known that I, JAMES C. SEAMAN, a citizen of the United States,resident of Collinwood, county of Cuyahoga, and State of Ohio,have-invented a new and useful Improvement. in Lightning-Arresters, ofwhich the following'is z1`specilication, the principle of the inventionbeing herein explained and the best inode in which I have vcontemplate-dapplying that principle, so as to distinguish it from other inventions.

As indicated` this vinvention relates to spark or lightning arresters,particularly to that type of lighting arrester in which the liuc isprotected Arom a i'ush of current by means of a chok: coil. ,As is wellunderstood, the sudden establishment in such a coil ofgtlie currentwhich followsv a lightning stroke or the like requires a. very greatelectromotive force. A narrow air gap being provided to ground, a sparkacross lsuch gap willfaccordingly be produced and being a comparativelygood conductor the reater portion of the rush of current wil passharmlessly by this path to earth. l

The object ot' the present invention is the provision of a device. ofthis general character that will he adapted to protect the line againsta rusli ot' curi-cnt in either direction, and that will be withaleconomicalfin construction and easily installed.

To the accomplishment of theseand related ends said. inventionconsistsjof the means hereinafter fully described and particularlyypointed out in the claims.

The annexed drawing. and the following description set forth' in 'detail'certain mechanism embodying th invention, such djs-y clo'sed meansconstituting, however, but one of various mechanical forms in which theprinciple of the. invention may be used.

In said annexed drawing: Figure l represents in perspective` a lightningarrester embodying my several improvements; Fig. 2 is a vertical centralsection of the same; Fig. 3 is a diagrammatic representation of sucharrester showing its connections; and Fig. 4 is a similar diagranmiaticrepresentation of connection. In such gures, then, A represcnts the baseor casing of the several parts of the device, such base preferablyconsisting of 'a solid block of orcelain, slate or other non-conductingre 'ractory material, suitably holiowed out on its under side to provideroom for the reception of such parts, the connections for which are onthe top of the base. These parts comprise essentially a choke coil B anda grounded terminal C separated from the respective terminals b b ofsuch choke coil by air gaps.

Such grounded terminal consists` preferablyy of a sk, orplete, 0 ofcarbon secured to the top of the base A by a screw c projected upwardlytherethrough and bearing a thuinb-nut o2 on its' upper end. Such screwand nut form a terminal for the at tacliinent of onel end of a conductorc3, Figs. 3 and. Il, leading to a suitable plate, not shown, embedded'inthe earthr or otherwise grounded.

In the first form of the choke coil B, illustrated in Fi s. l to 3,inclusive, such coil consists in e ect of two coils b Z' adapted to beserially connected in the line, ,the

-Wires b b" of which are 'attached to the binding posts providedinconnection with the respective terminals o b aforesaid. Each of the twocoils b" 7 2 coiisists of two terminelly joined conductors, Fig. 3, ofsuitable i size contiguously wound upon-iron cores b" but insulated from-eech other, by which.

means mutually opposing inductancesare developed, thus augmenting thechoking effect of the coil. The connection bs between the two coils isjoined by means of a short con ductor If with a. terminal b on the topof the. base A separated, like the terminals Z) b proper of the coil,'byan air gap from disk Y C constituting the grounded terminal of thedevice.

The modified form of the device illus-v -trated diagran'imatically only,F i 4, dii" coil. the arrangementof parts and conneca slightly modiliedtoi-m of the arrester. tions being otherwiseA the same, except that 50The .form in which t-lie instrument' is the additional sparking terminalb-connectshown in the figures just described is that ed with themid-point of the two coils is which, l preferably adopt when designingomittedthe same 'for use in connection with tele- The method'otinstallation as well as the graph or other signal lines, although withoperation of thedevicc should be suliiciently l??? practically nomodilication, except in size of parts, it is adapted for use in anyothei i out further dwelling thereon." It will be evident from theforegoing description withnoted, however, that by means of the abovedescribed construction I am enabled to eniploy` a single coil to choke asudden rush of current irrespective of the direction of tiow of the samealong the line, thus greatly enhancing the value of a device of thischaracter. The choke, in other Words, comes between two terminalsequally accessible to the ground plate providing a lcad from either`side of the arrester to ground each equally eiective. An additionaladvantage of prime importance arising from this construction is that thedevice, being reversible, cannot be put in wrongly but is fool proof.Where in addition connect the mid-point With a third terminal from whicha. current ofhigh potential may escape to ,such grounded terminal acrosstlie intervening air gap, it Will be seen that one coil may be burnedout without Wholly destroying the efiiciency of the device; theremaining' coil in most instances Wouldsuliice to still protect theline. The advantagegained in conipactness and increased eliicicncy bydoubling the conductor forming the coil so as to utilize the mutualindncta'nces thereby developed will be. quite'obvious.

Other ymodes of applying the principle ot' my invention may be employedinstead of the one explained, change being,r made as regards the`mechanism heroin disclosed, provided the meanC stated by any of thefollowing claims or the equivalent o-l" such stated means be employed. l

I therefore 'particularly point out and distinctly claim as my inventionl. in a device oi" thc chaiacter described, the combination oic :i baseoF nonconducting material, two choke coils inclosed in said base, theinner lends of said coils being connected and their outer ends extendingwith' out said base, whereby said coils may be con@ eeasoi nected inseries in a line, a conductor leading;` from the connection between saidcoils to a point contiguous to the outer ends oi the same, and agrounded terminal separated :trom the terminals of said coils and thatot' Said conductor, by air gaps, substantially as described.

2. ln a device of the character described, the combination of a base ofnon-conducting material, two choke coils inclosed in said base, theinner ends of said coils beineT connected and their outer ends extendingWithout one face of said base, whereby said coils may be connectedinseries in a line, a conductor leading from the connection between saidcoils to Idie saine tace of said base, and a grounded terminal on suchface separated from 'the terminals ot said coils and that ot' saidconductor by 'air `gaps, substantially asl described.

3. In a device of the character described,

the conibination of a base ot' non-conducting material, two choke coilsinclosed in said base, each ot' said cliol e'-"coils consisting of twoterminally joined conductors contiguously disposed in the coils butinsulated `trom each other, the inner ends of said coils being;-connected and their outer ends extendinn' withont'one 'face of saidbase, whereby said coils may be connected in series in a line, aconductor'leading from the connec-l tion between said coils to the saine.tace otn said base. and a grounded terminal on such tace separated'troni the lerniinalsl ot said' coils and tbat'ot' said conductor by air2flaps, substantially as described. Y

Signed by me, this 26th day oi' ctobcr,

lllOT.

JAMES (l. SllAli/IAN. ilitteslod by:

llll. R. Roni),

JN0. if. OnnamN.

